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'05 AC Problems, possible Blockage or really the Compressor?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by creature0077, Jul 4, 2014.

  1. creature0077

    creature0077 Junior Member

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    It's one of those days again when the temps are starting to get hot here in Austin, Tx. My AC started acting up during the Spring and first started working fine then after about 10-15 minutes of driving the air starts to blow warmer. The air doesn't go back to cold unless the car has been parked and off for several hours or overnight, and even after that it only blows cold for 10-15 mins again.

    Well, I didn't have the time/money to mess with it. The recent May it stopped cooling completely. I recently took it to a local shop and we look at it together. Drained the system and the mechanic was saying it's pulling some air and a little refrigerant. Well, we recharged the system and we could only put in 0.5 lbs and the Low side just maxes out. The system is supposed to hold 1.06 lbs so we were left scratching our heads.

    Decided to check for leaks, discharged the system again and hooked up a vacuum pump and see if the gauges will go below 0 for negative pressure and they never did. So the shop doesn't think my system has a leak. They could have used a dye to check but didn't have any on the shelf at that moment.

    I also have a DTC code of B1476 and we followed the shop manual. Fans blow into the engine and sometimes we had the bubble but couldn't add more refrigerant due to the Low side being maxed. (n)

    My father thinks I most likely have a blockage somewhere in the system. If so, does anyone have a suggestion on how I can check for this? Is there a specific place or two I can look to find out the system is blocked? :confused:

    Some people on the form seem to have AC problems, including some with the B1476, and others that couldn't find the problem very well. I'm worried that replacing the compressor wouldn't solve the problem, especially if there is a blockage or something. The local shop quoted me $1200 to replace the compressor and labor but they don't do hybrid systems normally so that has me a little concerned. My local Toyota dealership quoted $2600 for the same work which isn't possible for me to fork over.

    I usually do a lot of mechanic work but I've never actually worked on an AC system before. I would love to dive into this, even if I can only do part of it and then send it to the Toyota dealer for a flush and charge. (y)
     
  2. drmanny3

    drmanny3 Member

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    I kind of went through what you are experiencing. I think your problem is probably the compressor is going bad. My AC worked when first started but then would falter. It was not a leak, and I checked the fans on the radiator to insure they were working. I did notice that the compressor was much louder after running for a while then it had been before. I also replaced the AC amp unit, but that did not help. In the end I had to buy a new compressor. While you can get them on line or even rebuilt, I would recommend to go with a new one and have Toyota do the work. The compressor requires a special type of oil that can easily become contaminated with other oils often used in AC. It ended up costing me about $1200 and that was with Toyota chipping in on the parts. It takes a lot of effort to bleed the system and make sure it is properly filled. If you intend to keep the car I would have Toyota fix it. I am reasonably capable as a mechanic. I changed out the water pump and flushed the system, changed the plugs, etcetera. But AC is not my bag and I don't have the equipment to do it right. If money is a real object you could always try and buy it, install it and then have Toyota pull the vacuum and fill it. The AC compressor runs off of the traction battery so it is high voltage and you should be careful.
    Manny
     
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Given the presence of DTC B1476 and your statement that there does not appear to be a leak in the system, it is likely that the compressor motor is failing. It may work for a brief period, allowing the system to cool, then the motor draws excessive current which causes the inverter to reduce power to the AC compressor and log the DTC.

    You might install a replacement compressor yourself, then take the car to the dealer to apply vacuum to the system and replace the refrigerant.
     
  4. creature0077

    creature0077 Junior Member

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    The more I search around the more likely it seems that it might just be the compressor. Can someone clarify this for me, are those regular recharge cans of r134a not supposed to be used in the Prius AC systems? Are we supposed to use a special hybrid r134a like from amazon. I understand the need to use ND-11 oil on everything related to the system, I'm just wondering if I should avoid using a local shop to vacuum and replace the refrigerant if it's actually supposed to be kept separated from the standard type. Does that make sense?
     
  5. drmanny3

    drmanny3 Member

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    PS. You need to be careful if a shop does the work and does not have clean lines. If the oil is contaminated it can affect the high voltage system. Something about the specific oil used is compatible with the hybrid system. You may try asking Toyota as a customer accommodation to help off set the costs. They did so in my case. The other thing you might do is buy the compressor (shop around for a Toyota unit) then go in and have Toyota bleed your system and then take the old one out and put the new one in and then come back and have Toyota pull a vacuum and then refill your system. Frankly the labor you save is probably not going to make that big a difference. I have read about people having other shops do it and then after a year the unit goes bad or something else happens. Think about the fact that you use the air everyday winter or summer and it is a good investment. You still may be able to buy the unit cheaper than what they will sell it to you. I had a Toyota dealer parts department meet a competitors (another Toyota dealership) price. That could save you some money. Also Costco will give you a 15% discount on repairs from a participating dealer. Just go to Costco site and then to automobiles. You will see a section on service and there you can find out who in your area will honor the discount.
    Manny
     
  6. creature0077

    creature0077 Junior Member

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    I'm an EE and often work with high voltage so this would be a daily thing for me. :cool:
     
  7. drmanny3

    drmanny3 Member

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    Yes you need to be careful to keep from contaminating the system. As I understand it uses regular refrigerant. You can verify that by checking with Toyota. The problem you will encounter if you do it yourself is that you will end up allowing the refrigerant to escape into the atmosphere. Probably not the end of the world but a lot of people who drive Prius as well as electric vehicles care about the planet. So keep that in mind.
    Manny
     
  8. drmanny3

    drmanny3 Member

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    I was going to do it myself as well. I mean you just unplug the unit. So I am not too concerned. It might be worth paying Toyota the money to do the diagnostic to insure it is the compressor. That would at least let you know that you were not wasting your money. Toyota would probably agree to use the diagnostic money towards the repair. And then you could shop the compressor and get the best price. I think I saw them for about $600 new. A junk yard is another way to go. Problem is you are probably getting an old unit. Not worth the labor.
    Manny
     
  9. creature0077

    creature0077 Junior Member

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    I've already had the system drained at my local shop since I was planning on getting it taken care of soon.
     
  10. creature0077

    creature0077 Junior Member

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    New unit with compresser, seals, drier, and something else is available from RockAuto for $500. I wouldn't bother with a junkyard pull, too much work.
     
  11. creature0077

    creature0077 Junior Member

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    Is this guy talking about the expansion valves when he mentions the orifice tube?
     
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  12. Mike500

    Mike500 Senior Member

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    Originally, air conditioner used a thermostatic controlled expansion valve just like the large commercial units.

    In the late 1970's and early 1980's, many smaller units replaced the expansion valve with orifice tubes.

    Today, most auto air conditioners use orifice tubes.

    The effective function is nearly the same.
     
  13. creature0077

    creature0077 Junior Member

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    Are you saying the Prius has an orifice tube? If so, do you know the part number?
     
  14. Expo Prius

    Expo Prius New Member

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    Can someone tell me where the orifice tube is located? I got a new condenser installed but I'm only getting 40 psi out the high side. The compressor runs but I don't see much movement through the sight glass.
     
  15. creature0077

    creature0077 Junior Member

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    There is no "orifice tube" per se, but closest thing is called a cap in the condenser. I think it performs a similar function to the orifice tube but you won't fit an "orifice tube" in the parts listing.

    The cap is located on the bottom of the condenser near the cylinder on the side. You should be able to screw it out and check to see if there are metal shavings in there. Also can check the drier too. Problem with opening this is that you will need to evacuate the system again since you are letting air and moister inside.

    The sight glass isn't supposed to have much movement, for proper functions it's actually supposed to have no bubble after it's already running.

    I replaced my compressor, condenser, and expansion valve 2 months ago and had it recharged and everything is working well so far. Did all the work except the recharge myself.

    [​IMG]
     
  16. Expo Prius

    Expo Prius New Member

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    Very cool, thanks creature. So I should be OK on that since I installed a new condenser. I think my next step is to change the expansion valve once I figure out where it is and if that doesn't fix it then I'll change the compressor.
     
  17. creature0077

    creature0077 Junior Member

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    The expansion valve was a b$#*&. You're required to replace it whenever you replace the compressor to keep the warranty of the compressor intact. I assume you don't have the shop manuals? The expansion valve is located in the interior of the car under the dash near the firewall. It took me several hours to get to it and pretty much ripping apart the whole dash.

    [​IMG]
    [​IMG]
    [​IMG]
     
  18. creature0077

    creature0077 Junior Member

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    Btw, it's located on the passenger's side behind the blower unit. I was able to get to it without removing the blower unit completely, but it wasn't easy. Still had to take off most of the dash. Now I forgot to connect something so there is a rattle somewhere in the dash, gotta rip it apart again to see what I forgot to fasten down.
     
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  19. Expo Prius

    Expo Prius New Member

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    Whoa! I don't want to do all that. I think I'll take a chance and replace the compressor first. No shop manual but it's one of my next tools. Time to hit ebay. Thanks again creature.
     
  20. Expo Prius

    Expo Prius New Member

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    Well I have cold air again! Solved by changing the compressor however I must say that after removing the old compressor there was no oil pouring out of it sooo maybe the problem could have been due to low oil level? I added 2 ounces of oil directly into my new condenser when I changed it not knowing the compressor was probably dry. Rookie mistake or not, I took the compressor apart and found some damage. After installing the new compressor I used the bypass method to prime the system with r134 by jumping pins 1 and 4 on the pressure switch connector. I then removed the jumper to complete the refill process. Thanks to everyone who has contributed to the forum and a special thanks to creature, I did not have to change my expansion valve which saved me several hours of work! I'll see if I can upload some pictures of the damaged compressor tomorrow.
     
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